Loans Receivable and Allowance for Loan Losses - Analysis of Loans Modified in Troubled Debt Restructuring by Type of Concession (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2015 USD ($) Loan	Dec. 31, 2014 USD ($) Loan	Dec. 31, 2013 USD ($) Loan
Financing Receivable, Modifications [Line Items]
Number of Loans | Loan	162	21	14
Recorded Investment | $	$ 7,457	$ 1,080	$ 1,238
Extended under forbearance
Financing Receivable, Modifications [Line Items]
Number of Loans | Loan	1	11	0
Recorded Investment | $	$ 183	$ 460	$ 0
Interest-rate reductions
Financing Receivable, Modifications [Line Items]
Number of Loans | Loan	161	10	14
Recorded Investment | $	$ 7,274	$ 620	$ 1,238